- Joined
- Sep 19, 2001
- Messages
- 8,968
You are correct in that edge angle changes thickness for a set height from the edge, but when the knife is compound ground, the thickness of the blade before sharpening of course dictates the greatest possible thickness. The scandi grind provides the greatest example of that. Compare that to a full height hollow grind, and even with an identical edge angle, say 20 degrees included, there will be a large difference in effort needed to make a cut deeper than the height of the edge bevel.
Also, I was quoting the difference for a thinner primary couple with the lower angle, this was a total overall improvement between grind profiles and not just angle. Jsut angle still gives 3 to 5 times the improvement. The test was conducted so long ago, and I have been repeating myself without referencing the numbers. But yes, you can get quite close to ten times the cutting performance by dropping the grind thickness before sharpening to about ten thousandths from a respectable twenty, and also going to about 20 degrees included instead of 50. Now imagine, or actually measure if the knives are available to you, the difference between effort in cutting a pile of rope/cardboard/wood with a 'heavy duty chopper' with a primary grind stopping at fifty thousandths, and an edge grind of 30 degrees per side versus a knife taken to ten thousandths before an edge grind of 20 degrees total. This is one thing that leads me quite far away from such heavy edges. Yes, they can stand the abuse of heavy cutting, but they also need the abuse of heavy cutting because you cannot cut lightly. It is almost like wanting a less aerodynamic body design for a vehicle just so you can stuff a larger motor in it to force it to cut through air resistance with much worse fuel economy.
Also, I was quoting the difference for a thinner primary couple with the lower angle, this was a total overall improvement between grind profiles and not just angle. Jsut angle still gives 3 to 5 times the improvement. The test was conducted so long ago, and I have been repeating myself without referencing the numbers. But yes, you can get quite close to ten times the cutting performance by dropping the grind thickness before sharpening to about ten thousandths from a respectable twenty, and also going to about 20 degrees included instead of 50. Now imagine, or actually measure if the knives are available to you, the difference between effort in cutting a pile of rope/cardboard/wood with a 'heavy duty chopper' with a primary grind stopping at fifty thousandths, and an edge grind of 30 degrees per side versus a knife taken to ten thousandths before an edge grind of 20 degrees total. This is one thing that leads me quite far away from such heavy edges. Yes, they can stand the abuse of heavy cutting, but they also need the abuse of heavy cutting because you cannot cut lightly. It is almost like wanting a less aerodynamic body design for a vehicle just so you can stuff a larger motor in it to force it to cut through air resistance with much worse fuel economy.
